(1) Field of the Invention:
The present invention relates to an adhesive coating material for a hard tissue, which comprises a specific polymer and a specific compound in combination. More particularly, the present invention relates to an adhesive coating material for a hard tissue, which comprises (1) a polymer having an acid value of 30 to 700 and including in recurring units a hydrophobic group and two carboxyl (--COOH) groups or one carboxylic anhydride ##STR2## group bonded to the polymer, said carboxyl groups or carboxylic anhydride group being bonded to adjacent carbon atoms, and (2) an organic titanate compound.
(2) Description of the Prior Art:
Various compounds are known as adhesives having particular applicability in specific fields. Among these adhesives, especially severe requirements are imposed on dental adhesives used for bonding to hard tissues under humid condition. Since a dental adhesive is used in the oral cavity, a high adhesion strength in the humid condition is required. Furthermore, this dental adhesive should have an adhesive force to both of hard tissue and a dental resinous restorative material comprising a polymerizable monomer and at least one member selected from inorganic, organic and inorganic/organic composite fillers.
As dental adhesives, an ionomer cement comprising an aqueous solution of polyacrylic acid and inorganic oxide, and a cold-setting adhesive comprising a polymerizable monomer are widely used.
The Ionomer cement has an adhesive force to the hard tissue, but no adhesive force to a dental resinous restorative material. And the Ionomer cement is readily separated from the bonded portion since its water resistance is low.
The cold-setting adhesive comprising a polymerizable monomer hardly adheres to the hard tissue without pretreatment. Accordingly, it is necessary that the hard tissue should be treated with a highly concentrated aqueous solution of phosphoric acid to prepare a mechanical retentive surface. This method, however, is defective in that even healthy hard tissue is damaged since phosphoric acid is used at a high concentration.
Special properties are required for adhesives according to application fields thereof, and a certain adhesive usable in a certain field can seldom be used industrially in other fields. Accordingly, special adhesives are used in respective application fields, and also in the field of the dental treatment, development of an adhesive satisfying the foregoing requirements is eagerly desired.